Feed control and indicating mechanism for a grinding machine



April 3, 1962 K. H. SCHULTZE FEED CONTROL AND INDICATING MECHANISM FOR A GRINDING MACHINE 5 Sheets-Sheet 1 Filed Jan. 28, 1959 i i lli Inventor? Kurf H Schu/T'ze April 3, 1962 K. H. SCHULTZE 3,027,691

FEED CONTROL AND INDICATING MECHANISM FOR A GRINDING MACHINE Filed Jan. 28, 1959 3 Sheets-Sheet 2 96 52 i d J' F 7 -1 I 192 I t -li'lil 402 6 6 pg d0 d4 Fig.5

Inventor. Kur-T H. Jc/w/Tze wlf as April 3, 1962 K. H. SCHULTZE 3,027,553I

FEED CONTROL AND INDICATING MECHANISM FOR A GRINDING MACHINE Filed Jan. 28., 1959 3 Sheets-Sheet 3 a mu United States Patent Ofiiice iiflz'lfiiil Patented Apr. 3, 1962 firm Filed Jan. 28, 1959, Ser. No. 789,708 Claims priority, application Germany Feb. 1, 1958 Claims. (Cl. 51-165) The invention relates in general to grinding machines and in particular to a new and useful thread grinding machine including agrinding wheel dressing tool and means for automatically indicating and controlling the extent of the'feedof thegrindirig' wheel either toward the dressing tool for dressingpurposes or toward the work piece for grinding thereof.

This invention is an improvement over devices of this character, particularly in respect to the mounting of a dressing tool on-one side of a grinding. wheel and a mounting of the work piece on the opposite side, and including a hand control for the feeding of the grinding wheel into engagement with the dressing tool for dressing thereof or into engagement with the work piece for finishing thereof. The arrangement includes a setting control for indicating and stopping the feed of the grinding wheel toward the work piece during a grinding run thereof and for also indicating and controlling the feed of the grinding wheel in an opposite direction toward the dressing tool for controlling the dressing of the grinding wheel. The control mechanism includes two additional control rings which rotate in proportion to, but at a much slower speed than the hand wheel feed in order to indicate the total number of hand wheel rotations in either direction during a dressing pass or a grinding pass.

Thus, it is possible with the apparatus of the invention to advance the grinding wheel into engagement with the dressing tool and dress the grinding wheel down to a predetermined amount as controlled by indicating mechanism associated with the feed. The precise amount of which the grinding wheel is dressed is indicated, and this indication is used to adjust a setting on the feed control to permit allowance for the reduction of the diameter of the grinding wheel during a pass over the work piece. If desired, one setting can be made for a dressing run followed by a grinding run. The setting makes full allowance for the reduction of the diameter of the grinding wheel during dressing, and the amount of grinding wheel feed during a grinding pass is increased proportionately.

Accordingly, it is an object of this invention to provide an improved grinding mechanism feed control.

A further object of this invention is to provided a grinding device including means for advancing a grinding wheel in one direction toward a dressing tool and thereafter in an opposite direction toward a work piece and means for controlling the feed in each direction.

A further object of this invention is to provide a grinding device including a centrally located grinding wheel movable in one direction into engagement with a dressing tool and movable in an opposite direction into engagement with a work piece, including means for indicating and correctly compensating for the reduction in diameter of the grinding wheel due to a dressing operation thereon by the dressing tool and for correcting the feed of the wheel into association with the work piece in correspondence with such reduction in diameter.

A further object of this invention is to provide a reduced speed indicating means to indicate the total revolutions of a grinding wheel hand feed control.

A further object of this invention is-to provide a grind- 2 ing device which is simple in design, rugged in construction and economical to manufacture.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated and described preferred embodiments of the invention.

In the drawings:

FIG. 1 is a somewhat schematic fragmentary side elevation, partly in section of a thread grinding machine constructed in accordance with the invention;

FIG. 2 is a fragmentary end elevation of a portion of Y the grinding wheel feed indicating and control mechanism of the thread grinding machine illustrated in FIG. 1;

FIG. 3 is a fragmentary transverse section through the hand wheel grinding wheel feed control of the thread grinding machine illustrated in FIG. 1;

FIG. 4 is an end elevation of the additional feeding indicating rings of the thread grinding machine indicated in FIG. 1;

FIG. 5 is a fragmentary transverse section similar to FIG. 3 of another embodiment of the invention;

FIG. 6 is a somewhat schematic end elevation of the gearing mechanism connected to the feed control for the grinding machine indicated in FIG. 5; and

FIG. 7 is a schematic fragmentary end elevation of the additional feed indicating rings and stops of the embodiment illustrated in FIG. 5.

Referring to the drawings in particular, the invention as embodied therein includes a thread grinding machine generally designated 10 including a centrally disposed grinding wheel 12 which is rotatably mounted on a carriage 14, the latter being transversely reciprocable between end frame members 16 and 18.

A grinding wheel dressing tool 21) is mounted on an upstanding member 22 atop the end frame member 16.

A work piece 24 is mounted on a work carriage 26 and is laterally shiftable on the end frame member 18 transverse to the path of movement of the grinding wheel 12.

In accordance with the invention, the grinding Wheel 12 may be advanced a predetermined amount under a controlled setting to effect the dressing down of its peripheral surface by the dressing tool 240 an amount such as indicated in FIG. 1. at a. For this purpose, the carriage 14 is provided with a depending screw nut 28 which is internally threaded and rides on a screw spindle 30 and is advanced axially therealong upon rotation of the spindle 30. The screw spindle 39 is connected at one end to a hand feed control wheel generally designated 32. The hand wheel 32 is provided with a handle extension 34 which permits easy rotation of the wheel 32 and the spindle 30 to move the grinding wheel 12 into association with the dressing tool 20, when the dressing of the wheel is to be effected, and to thereafter move it into association with the work piece 24 when grinding of the work piece is to be accomplished.

In accordance with the invention, the amount of rota tion of the hand wheel 32 and hence the advance of the grinding wheel 12 into one direction or the other is precisely set by indicating and control means in order to make certain that the work piece is accurately machined, both before and after dressing of the grinding wheel. When the grinding wheel 12 is moved, an amount for the reduced diameter of the grinding wheel and to spar 4591 permit the grinding wheel to advance into the work piece an amount sufficient to give the desired cut during a werlt feeding pass.

v The hand wheel 32 is provided with a hubbed portion 36 upon the outer periphery of which is positioned a pair of calibrated control rings 38 and 40 provided for indicating and controlling the amount of feed of the grinding wheel 12 toward the dressing tool 20, and toward the work piece 24, respectively. Each control ring 38 and 40 is provided with an outstanding portion or lug 4-2 and 44, respectively, which may be rotated in opposite directions away from a stop member generally designated 46 in order to permit unhindered rotation of the hand wheel 32 until the lugs are brought back to a position at which they contact a portion of the stop member 46.

The stop member 46, as best indicated in FIG. 2, includes a central control handle or knob 48 forming the base of a substantially inverted T-shaped member including an arm with a depending stop 50 and another arm at the opposite end of the T with a depending stop 52. When the knob 48- is positioned in the dotted line position indicated in FIG. 2, the stop 50 is in position to engage the lug 42 whenever it is rotated into contact therewith. When the hand control wheel 32 is rotated in a direction to advance the grinding wheel into engagement with the work piece 24 the lug 42 also rotates until it contacts stop 58, indicatin'g the end of the grinding pass. When the grinding wheel 12 is to be moved in the direction of the dressing tool 20, the handle 48 is moved to the right to position the stop 52 on the disc 40 at which position itwill intercept: the lug 44 when it is rotated by the hand wheel 32% advance the grinding wheel toward the dresstool 20. Thus, it can be seen that the amount which the lugs 42 and 44 are displaced from the stops 50 and 52 will determine the amount which the hand wheel 32 can be rotated in either direction. I

In order to provide a means for indicating the amount which the grinding wheel 12 has been advanced after it is positioned in contact the dressing tool 20 and hence the amount of the reduction of its diameter, there is provided aii additional advance indicating mechanism (FIG; which includes a hubbed disc generally desighated 54 which is atfixed to the frame member 18 by means of a screw bolt 56. The hubbed disc 54 is provided with an internal gear 58 which meshes with a gear portion 60 which forms part of a double gear generally designated 62. The double gear 62 is rotatably mounted on a bolt member 64 aflixed to the hubbed hand wheel portion 36. The double gear 62 is provided with another gear portion 66 which meshes with an internal gear 67 of the hubbed ring 68 which is rotatably mounted on the hubbed disc generally designated 54.

A flanged ring 70 is positioned on the outer periphery of the hubbed ring 68 and is held thereon for rotation therewith by a plurality of bolts 72 which are tightened in position by nuts 74 acting against the force of a spring 76. A pair of indicating rings 78 and 80 are rotatably mounted on the flanged ring 78 and are held in frictional contact with outer portions of the flanged ring 70 and the hubbed ring 68 and a central spacer ring 82. A plu- 'rality of pins 84 extend radially outwardly from the flanged ring 70 into recesses of the spacer ring 82 to efiect rotation of this ring along with the hubbed ring 68. Rotation of the hand wheel 32 is effective to rotate the hubbed ring 68 and the flanged ring 70, but the rings '78 and 80 are frictionally held and their rotation may be interrupted by a force of a predetermined amount as controlled by the spring 76, without stopping the rotation of the hand wheel 32.

In accordance with the invention, a stop member generally designated 83 is mounted on the end frame 18 and includes a depending stop lug 85 and 86 at each end which overlies each of the rings 78 and 80, respectively. In accordance with the invention, the rings 78 and 80 are provided with graduations thereon to indicate the advance of the grinding wheel 12 which would be produced by a certain rotation of the hand Wheel 32. Each ring 78 and 80 is provided with an upstanding projection or lug 88 and 90, respectively, which are rotated to a preselected setting position away from the depending stop lugs 85 and 86 and are permitted to contact the stop lugs to be held thereby independently of the hand control wheel 32 in order to indicate the amount of additional rotation of the same after the hand wheel has been brought into contact with the dressing device, for example. The rings 78 and may be set initially with the lugs 88 and 90 against the stop lugs 85 and 86 so that rotation of the hand wheel will indicate the total linear distance of movement of the grindwheel 12 from the start of feeding in any direction. Since the rings 78 and 80 rotate at a much slower rate than the hand wheel 32 due to the reduction gearing, an indication of the number of revolutions of the hand wheel may be easily obtained.

If desired, the rings 78 and 80 need not be set to a zero position against the stop lugs 85 and 86 until the hand wheel is rotated to bring the grinding wheel 12 into a position at which it just contacts the Work piece. Thereafter, rotation of the hand wheel will cause one of the rings 78 or 80 (depending on which direction the hand wheel is rotated) to be rotated relativev to the hubbed ring 68 so that an indication of the linear distance of movement of the grinding wheel 12 toward the dressing tool as it is being dressed (and hence an indication of the amount which the surface thereof is undercut), may be readily indicated. This indication may be used to correct the setting of the control rings 38 and 40 in order to achieve the correct feeding movement of the grinding wheel 12 during a grinding pass.

The internal parts of the feed control and indication mechanism are lubricated through a series of connected passages 92, 94, 96 and 98, the lubrication passages being covered by a nut 100 aifixed to the center of the hand wheel 32.

In order to evenly distribute the pressure exerted by the hand wheel 32 against the assembly of rings, the hand wheel 32 is formed with an annular pressure surface 102 which abuts against a member 104 which is biased outwardly by a spring 105 against the surface 102.

In the embodiment illustrated in FIGS. 5 to 7, a screw spindle 106 comparable in function to the screw spindle 30 is advantageously provided with a hand wheel 107 to rotate a series of gears 108, 110, 112, and 114, the latter of which is aflixed to a shaft 116. The gear ratio is such that one full revolution of the hand wheel affixed to the screw spindle shaft 106 will effect a 20 angular rotation of the gear 114. This is in the ratio of 1:18 but the ratio may be varied and a ratio of say 1:10 would be suitable.

The gear 114 is provided with an outer ledge portion 118 which supports a pair of indicating rings 120 and 122 which are rotatably mounted in respect thereto. The rings are spaced apart by a spacer ring 124 and are held frictionally between the portion 118 and a collar member 126 which is biased against the outer ring 120 by a spring 128 retained by a collar 130 affixed to the shaft 116. The spacer ring 124 is provided with a plurality of radially spaced slots into which pins 127 aflixed on the gear ledge portion 118 extend. Each of the indicating rings 120 and 122 is provided with a laterally inwardly extending abutment 132 and 134, respectively, which are positioned on opposite sides of an elongated stationary bar 136 aflixed to the end frame member. Thus, rotation of the screw spindle 106 by means of the hand wheel 107 affixed thereto will cause one of the members 132 or 134 to move against the elongated stationary member 136 (depending on which direction the hand wheel is rotated), and efiect rotation of its associated ring 120 or 122. This relative rotation of the rings is indicated on an associated scale and may be used to correct the feed setting of the device as indicated previously.

This application is a continuation-in-part of my application Serial No. 758,935, filed September 4, 1958.

While specific embodiments of the invention have been shown and described in detail to illustrate the application of the invention principles, it will be understood that the invention may be embodied otherwise without departing from such principles.

What is claimed is:

1, In a grinding machine including a frame, a dressing tool mounted on one side of said frame, a work carriage mounted on the opposite side of said frame, a wheel carriage shiftable on said frame between said work carriage and said dressing tool, a grinding wheel rotatably mounted on said wheel carriage, the improvement comprising a screw spindle rotatably mounted on said frame beneath said grinding wheel and extending from one side of said frame to the other, said wheel carriage including a depending nut internally threaded and engaged with said screw spindle, a hand wheel connected to said screw spindle for rotating the latter and moving said wheel carria ge from one side of the machine to the other, said hand wheel including a hubbed cylindrical portion, a first and a second calibrated control ring rotatable on said cylindrical portion and comprising outstanding lug portions, a stop member connected to said frame, overlying said control rings and positionable in the path of said lug portions, said control rings being displaceable away from said stop member so as to move said lug portions on opposite sides of said stop member a predetermined amount away therefrom corresponding to the desired movement of said grinding wheel selectively toward said ressing tool and said work carriage, means for frictionally holding said rings to said cylindrical portion for rotation therewith, whereby said lug portions are brought into engagement with said stop member upon rotation of said screw spindle in a direction to rotate the associated one of said lug portions toward said stop member, an indicating ring rotatably mounted on said hand wheel, said frictionally holding means including means for rotating said indicating ring at a lesser speed than said hand wheel, a second stop member depending from said frame, said indicating ring having an outstanding lug movable into the path of said second stop member, and means to permit interruption of rotation of said indicating ring by contact with said second stop member upon continued rotation of said hand wheel, whereby to indicate the amount of rotation of said hand Wheel and displacement of said grinding wheel after said indicating ring is contacted by said second stop member, and scale means to indicate relative movement of said hand wheel and all of said rings.

2. In the combination according to claim 1, the improvement further comprising a second indicating ring connected to said hand wheel adjacent said first indicating ring and having a second outstanding lug positioned on the other side of said second stop member, whereby to cause said second stop member to hold said second indicating ring upon rotation of said hand Wheel in a direction to bring said second outstanding lug into contact with said second stop member.

3. In the combination according to claim 2, the improvement further comprising a hubbed ring gear member having an internal gear and wherein both of said indicating rings are frictionally held on said ring gear member, and gear means connected to said hand wheel and said ring gear member for rotating the latter at a lesser speed than said hand wheel.

4. In the combination according to claim 2, the improvement further comprising a hubbed ring gear member, a flanged ring member on said hand wheel for frictionally holding said indicating rings, and gear means connecting said screw spindle and said flanged ring member for rotating the latter at a lesser speed than said screw spindle.

5. A feed control and indicating mechanism for a grinding machine including a central rotating grinding wheel laterally shiftable to a position in operative association with a work piece and to a position in operative association with a dressing device disposed on the opposite side thereof from said work piece, comprising rotatable means for shifting the position of said grinding wheel, rotating indicating ring means adjacent said rotatable shifting means, drive means connected to said rotatable shifting means and said indicating ring means to drive the latter at a lesser speed than said rotatable shifting means, said indicating ring means including a cylindrical portion, and at least one calibrated ring portion frictionally held on said cylindrical portion but manually rotatable thereon against the force of friction, said indicating ring means including at least one outstanding portion, a fixed stop located adjacent said ring portions and disposed in the path of rotation of said outstanding portions, said ring portions being displaceable away from said stop.

References Cited in the file of this patent UNITED STATES PATENTS 1,514,352 Taylor et a1. Nov. 4, 1924 1,640,992 Hanson Aug. 30, 1927 FOREIGN PATENTS 264,786 Great Britain June 30, 1927 

